Instrument with expandable member configured to prepare a penis for implantation of a penile prosthetic

ABSTRACT

An instrument configured to prepare a penis for implantation of a penile prosthetic includes a rigid shaft extending between a proximal end and a distal end that is insertable into the penis, and an expandable member coupled to a distal end portion of the shaft. The expandable member is movable between a first position having a first diameter that is substantially equal to a diameter of the rigid shaft and a second position having a second diameter that is larger than the diameter of the rigid shaft and configured to dilate tissue of the penis.

BACKGROUND

Implanted penile prostheses address erectile dysfunction in men.

In a typical implantation procedure, the penis of the patient is incisedin a corporotomy to expose a pair of corpora cavernosa that are alignedaxially in a side-by-side orientation within the penis. A cuttingimplement, such as a curved Mayo scissors, is employed to penetrate thefascia of the penis and form an opening accessing each corporacavernosum. Thereafter, a tool (e.g., a “Furlow” introducer) is insertedinto each corpora cavernosum to measure a length of the penis distallyand proximally from a “stay” suture or other stationary landmark locatednear the opening formed in the fascia. Subsequently, each corporacavernosum is dilated with at least one separate dilation tool, andoften multiple dilation tools. For example, each corpora cavernosum isdilated by introducing gradually larger stainless steel rods into thecorpora cavernosum to form a recess in the penis that is sized toreceive a cylinder of the penile prosthesis.

The above-described procedure has proven effective in the implantationof penile prostheses. However, practitioners have expressed a continuingdesire for more efficient and cost effective tools and procedures forimplanting penile prostheses.

SUMMARY

One aspect provides an instrument configured to prepare a penis forimplantation of a penile prosthetic. The instrument includes a rigidshaft extending between a proximal end and a distal end that isinsertable into the penis, and an expandable member coupled to a distalend portion of the shaft. The expandable member is movable between afirst position having a first diameter that is substantially equal to adiameter of the rigid shaft and a second position having a seconddiameter that is larger than the diameter of the rigid shaft andconfigured to dilate tissue of the penis.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of embodiments and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments andtogether with the description serve to explain principles ofembodiments. Other embodiments and many of the intended advantages ofembodiments will be readily appreciated as they become better understoodby reference to the following detailed description. The elements of thedrawings are not necessarily to scale relative to each other. Likereference numerals designate corresponding similar parts.

FIG. 1 is a cross-sectional view of one embodiment of an instrumentconfigured to prepare a penis for implantation of a penile prosthetic.

FIG. 2 is a cross-sectional view of a shaft of the instrumentillustrated in FIG. 1.

FIG. 3 is a side view of a plunger of the instrument illustrated in FIG.1.

FIG. 4A is a cross-sectional view of a distal end portion of theinstrument illustrated in FIG. 1.

FIG. 4B is a cross-sectional view of the distal end portion of theinstrument illustrated in FIG. 1 showing three different controlledexpansion configurations for an expandable dilation member of theinstrument.

FIG. 5A is a cross-sectional view of the instrument illustrated in FIG.1 primed by aspirating liquid into an internal fluid chamber accordingto one embodiment.

FIG. 5B is a schematic view of the primed instrument illustrated in FIG.5A in a configuration to measure a corpora cavernosa of a patient.

FIG. 5C is a cross-sectional view of one embodiment of the liquid withinthe fluid chamber pressurized by the plunger to dilate the distal endportion of the instrument for dilating the corpora cavernosa of thepatient prior to implantation of the penile implant.

DETAILED DESCRIPTION

In the following Detailed Description, reference is made to theaccompanying drawings, which form a part hereof, and in which is shownby way of illustration specific embodiments in which the invention maybe practiced. In this regard, directional terminology, such as “top,”“bottom,” “front,” “back,” “leading,” “trailing,” etc., is used withreference to the orientation of the Figure(s) being described. Becausecomponents of embodiments can be positioned in a number of differentorientations, the directional terminology is used for purposes ofillustration and is in no way limiting. It is to be understood thatother embodiments may be utilized and structural or logical changes maybe made without departing from the scope of the present invention. Thefollowing detailed description, therefore, is not to be taken in alimiting sense, and the scope of the present invention is defined by theappended claims.

It is to be understood that the features of the various exemplaryembodiments described herein may be combined with each other, unlessspecifically noted otherwise.

The term “proximal” as employed in this application means that thereferenced part is situated next to or near the point of attachment ororigin or a central point: as located toward a center of the human body.The term “distal” as employed in this application means that thereferenced part is situated away from the point of attachment or originor the central point: as located away from the center of the human body.A distal end is the furthest endmost location of a distal portion of athing being described, whereas a proximal end is the nearest endmostlocation of a proximal portion of the thing being described. Forexample, the glans penis is located distal, and of the crus of the penisis located proximal relative to the male body such that a distal end ofa corpora cavernosum of the patient extends about midway into the glanspenis.

Multiple different tools and instruments are employed in a typicalpenile prosthetic implantation procedure to form a recess sized toreceive the implant. In general, the fewer tools employed during a bodyimplant procedure, the better.

Embodiments provide an instrument that is configured to prepare a penisfor implantation of a penile prosthetic, where the instrument includes afirst state characterized by a substantially uniform shaft diameter thatis suited for measuring a length of a corpora cavernosa of the patient,and an expandable member that is configured to rigidly expand in alateral direction from the shaft dilate corpora cavernosa of thepatient. The expandable member, when expanded/dilated, is suited to coreand displace tissue in the corpora cavernosa of the penis. Theinstrument thus provides a combination measurement and dilation toolthat offers dilation of the corpora with improved procedural efficiency,which obviates the use of multiple different tools during theimplantation of a penile prosthetic to provide additional surgicalefficiencies.

FIG. 1 is a cross-sectional view of one embodiment of an instrument 20configured to prepare a penis for implantation of a penile prosthetic.The instrument 20 includes a shaft 22, a plunger 24 that is movablyinserted into the shaft 22, and an expandable member 26 coupled to theshaft 22.

The shaft 22 extends between a proximal end 30 and a distal end 32. Inone embodiment, the shaft 22 includes a fluid chamber 34 formed withinthe shaft 22, an orifice 36 formed in the distal end 32 thatcommunicates with the fluid chamber 34, and a fluid pathway 38 that isformed in the shaft to communicate between the fluid chamber 34 andexpandable member 26. The plunger 24 is movable within the shaft 22 toaspirate/draw liquid into the fluid chamber 34, and once the fluidchamber 34 is charged with liquid, the plunger 24 is movable to expandthe expandable member 26 to a wider dilation configuration.

The expandable member 26 thus is movable between a deflated state (asshown) and an inflated state (FIG. 4B). When the expandable member 26 isin the deflated state, the instrument 20 has a substantially uniform anduninterrupted diameter that is suited for insertion into the corporacavernosa for measuring a length of each corpora cavernosum of thepenis. In one embodiment, an exterior surface of the shaft 22 includesmeasurement markings 39 that allow the user to measure the length ofeach corpora cavernosa in centimeters. In one embodiment, the markings39 extend from zero centimeters at the distal end 32 of the shaft toapproximately 20 centimeters behind the distal end 32, although otherranges for the length measurement and other units of measure are alsoacceptable.

The plunger 24 is movable to inflate the expandable member 26 laterallyaway from the shaft 22, which places the expandable member 26 in theinflated state useful for dilating a diameter of each corpora cavernosumof the penis. The instrument 20 allows the approach of first measuringthe length of the corpora with the marking 39 on the shaft 22 asinserted into the corpora, and then expanding the expandable member 26to dilate the corpora while the shaft 22 is inside the corpora. Theinstrument 20 provides stops for the plunger 24 as it moves into theshaft 22 and the fluid chamber 34, as described below, to allow thecontrolled and selective expansion (e.g., dilation width) of theexpandable member 26.

FIG. 2 is a cross-sectional view of one embodiment of the shaft 22. Theshaft 22 includes a proximal end portion 40 that extends from theproximal end 30 and a distal end portion 42 that extends from the distalend 32. In one embodiment, the fluid chamber 34 is an axial bore formedin the shaft 22 and communicates with the orifice 36 formed in thedistal end 32 and with the expandable member 26 via the fluid pathway38.

The expandable member 26 is generally coupled to the distal end portion42 of the shaft 22. In one embodiment, the expandable member 26 is afilm that is sealed to at least a portion of an exterior side surface ofthe shaft 22, where the film is expandable to provide a bulb or dilationballoon. In one embodiment, the expandable member 26 is sealed aroundthe entire periphery of the shaft 22.

In one embodiment, the fluid pathway 38 is formed in the distal endportion 42 of the shaft 22 as one opening, or as a series of holes. Inone embodiment, the fluid pathway 38 is formed in the distal end portion42 of the shaft 22 as a slot section or a series of slot sections. Whilenot visible in the cross-sectional view of FIG. 2, portions of thesidewall of the shaft 22 extend between the proximal and distal endportions 40, 42 to provide the shaft 22 with structural rigidity alongits length.

In one embodiment, a check valve 50 is provided in the distal endportion 42 of the shaft proximal the orifice 36. The check valve 50 isconfigured to open to allow the orifice 36 to draw liquid into the fluidchamber 34 and to close to prevent the liquid within the fluid chamber34 from exiting the shaft 22 through the orifice 36. The check valve 50,when closed, functions to force the liquid as it is pressurized withinthe fluid chamber 34 by the plunger 24 to flow through the fluid pathway38, which expands the expandable member 26.

In one embodiment, one or more detents 52 are formed on an interiorsurface 54 of the shaft 22. The detents 52 cooperate with the plunger 24(FIG. 1) to provide for the controlled and selective pressurization ofthe fluid within the fluid chamber 34.

FIG. 3 is a cross-sectional view of the plunger 24. The plunger 24includes a rod 54, a handle 56 attached to a proximal end of 60 of therod 54, and a seal 61 attached to a distal end 62 of rod 54. The rod 54,the handle 56, and the seal 61 may be formed as a unitary monolithicpiece, for example via molding, or these components may be providedseparately and attached during fabrication. As an example, the rod 54and the handle 56 are suitably molded from polysulfone around a ring ofsofter polymer (e.g., silicone) that forms the seal 61.

In one embodiment, handle 56 is provided as a flange or as a pair ofopposing wings or other appendages that extend beyond the rod 54. Theflange allows the palm of the surgeon to press the plunger 24 into theshaft 22 (FIG. 2) and also provides a surface that allows the plunger 24to be withdrawn from the shaft 22 by, for example, the index and middlefinger of the surgeon.

In one embodiment, the rod 54 is formed to include a series of stopdetents 72 extending between the proximal end 60 and the distal and 62.With additional reference to FIG. 2, the stop detents 72 cooperate withthe detents 52 formed in the shaft 22 to allow the plunger 24 to bepressed into the shaft 22 at controlled, incremental intervals toselectively pressurize the fluid within the fluid chamber 34. Forexample, engaging the first stop detents 72 adjacent to the distal end62 with the detents 52 of the shaft 22 will pressurize the liquid in thefluid chamber 34 to a first pressure. Pressing the plunger 24 anadditional distance into the shaft 22, for example such that the stopdetents 72 adjacent to the proximal end 60 engage with the detents 52,will pressurize the liquid in the fluid chamber 34 to a second pressurethat is greater than the first pressure. The expandable member 26 isconfigured to respond to the pressure of the liquid within the fluidchamber 34 such that the expandable member 26 expands laterally awayfrom the shaft 22 as a function of the increase in the pressure of theliquid inside the fluid chamber 34, as illustrated in FIG. 4B.

In one embodiment, the stop detents 72 are formed as annular groovesaround the rod 54. In one embodiment, the stop detents 72 are formed ashelical grooves that are provided to enable the plunger 24 to be“screwed” into the detents 52 of the shaft 22.

In one embodiment, the instrument 20 is configured to be reusable and isfabricated from a suitable material such as a polymer or a metal.Suitable materials for the shaft 22 and the plunger 24 includepolysulfone, polyetherimide, polyester or blend or derivatives ofpolyester. One suitable material for the expandable member 26 is a thinsheet or film of polyester that is expandable when pressurized by liquidin the fluid chamber 34. In one embodiment, the shaft 22 and the plunger24 are each fabricated from polysulfone and the balloon 26 is formed ofa polyester film, which configures the instrument 20 for disposablesingle surgical use.

FIG. 4A is a cross-sectional view of the distal end portion 42 of theshaft 22. The shaft 22 has a uniform outside shaft diameter D1 when theexpandable member 26 is in the un-expanded state. In one embodiment, arecessed shoulder 80 is formed in the shaft 22 to receive opposing edgesof the expandable member 26. That is to say, the recessed shoulder 80provides the distal end portion 42 of the shaft 22 with a recessedsection, where the recessed section is recessed relative to the diameterD1 of the proximal end portion 40 (FIG. 2) of shaft 22. The expandablemember 26 is disposed in the recessed section such that when theexpandable member 26 is at rest (or deflated) the distal end portion 42of the shaft 22 has a cross-sectional corresponding with the diameterD1. Thus, in one embodiment the instrument 20 is provided with asubstantially uniform diameter between the proximal end portion 40 andthe distal end portion 42 of the shaft 22.

In one embodiment, the expandable member 26 is provided as a polyesterfilm and is sealed around a periphery of the distal end portion 42 ofthe shaft 22. The polyester film of the expandable member 26 isconfigured to balloon out when expanded and have sufficient rigidity toallow the instrument 20 to dilate the corpus spongiosum tissue withineach corpora cavernosa.

The check valve 50 is disposed in the distal end portion 42 of the shaft22 proximal the distal end 32. In one embodiment, the check valve 50 isa one-way ball valve having a ball 82 that is biased against a surface84 by a spring assembly 86. The one-way ball valve 50 is configured toallow liquid to be drawn from outside the shaft 22, through the orifice36, past the biased ball 82, and into the fluid chamber 34. When theliquid in the fluid chamber 34 is pressurized, the spring assembly 86forces the ball 82 to seat against the surface 84 and prevents theliquid from exiting the shaft 22 through the orifice 36. As aconsequence, the pressurized liquid flows through the fluid pathway 38and exerts a force on the expandable member 26.

In one embodiment, the check valve 50 is located proximal to theentrance to the orifice 36 to allow the distal end 32 of the instrument20 to be dipped “leading end first” into a container of liquid to allowfor the subsequent aspiration of liquid into the fluid chamber 34. Thus,the liquid loading port for the instrument 20 is located at the leadingend, which is the distal-most end 32 of the shaft 22.

FIG. 4B is a schematic view of the distal end portion 42 of theinstrument 20 illustrating activation of the expandable member 26. Thefluid chamber 34 has been charged with liquid L or “primed,” for exampleby retracting the plunger 24 in the proximal direction out of the shaft22 (FIG. 1). The expandable member 26 expands laterally away from theshaft 22 as a function of the increase in the pressure of the liquid Linside the fluid chamber 34 as the plunger 24 is pressed distally intothe shaft 22.

Instrument 20 is configured to measure the corpora by providing asubstantially uniform diameter D1 when the expandable member 26 isdeflated (e.g., when the pressure inside the fluid chamber 34 isbalanced with the pressure outside of the fluid chamber 34, which isdenoted herein as a pressure condition of P0). The expandable member 26expands laterally away from the shaft 22 as the pressure in the liquid Lwithin the fluid chamber 34 is increased, which configures theinstrument 20 for selective and controlled dilation of the corpora.

For example, at a first increased pressure of P1, the expandable member26 expands laterally away from the shaft 22 to provide a dilationdiameter of D2 for the instrument 20. The expandable member 26 expandslaterally away from the shaft 22 to a dilation diameter of D3 when thepressure is increased to a pressure of P2. The expandable member 26expands laterally away from the shaft 22 to a dilation diameter of D4when the pressure is increased to a pressure of P3. In one embodiment,the expandable member 26 is expanded laterally away from the shaft 22 ina controlled manner such that the expandable member 26 is maintained atthe dilation diameter of D2 associated with pressure P1. In oneembodiment, the expandable member 26 is expanded laterally away from theshaft 22 in controlled increments, for example from the dilationdiameter of D2 associated with pressure P1 to the dilation diameter ofD3 associated with the pressure of P2 and then maintained at thedilation diameter of D3.

The diameter size range between the diameters D1-D4 is selected basedupon the end use or desired end result. The diameter size range betweenthe diameters D1-D4 in one exemplary embodiment ranges from 2 mm to 20mm or more. In one embodiment, the diameter D1 is 8 mm, the diameter D2is 10 mm, the diameter D3 is 12 mm, and the diameter D4 is 14 mm. Thus,one embodiment of the instrument 20 includes an expandable member 26that is inflatable from the first diameter D1 to a second diameter D2that is larger than the diameter D1, where the second diameter D2 aranges between 100-200% of D1.

In one exemplary embodiment, the expandable member 26 is coupled to thedistal end portion 42 of the shaft 22 and is movable between a firstposition as illustrated in FIG. 4A having a first diameter D1 that issubstantially equal to a diameter of the rigid shaft 22 and a secondposition (for example, as shown by P2 in FIG. 4B) having a seconddiameter D3 that is larger than the diameter D1 of the rigid shaft 22and is thus so configured to dilate tissue in the corpora of the penis.

FIGS. 5A, 5B, and 5C are views, respectively, of the instrument 20primed by aspirating liquid into the fluid chamber 34, the primedinstrument 20 ready to measure a corpora cavernosa of a patient, and theexpandable member 26 dilated outward to provide the instrument 20 withan increased outside diameter for dilating the corpora cavernosa of thepatient.

FIG. 5A is a cross-sectional view of one embodiment of the instrument 20primed by aspirating liquid L into the internal fluid chamber 34. In oneexemplary approach, the surgeon (or a surgical assistant) presses theplunger 24 into the shaft 22 (as shown in FIG. 1) and dips the distalend 32 into a tray or container 90 of liquid L. The plunger 24 has beenretracted proximally (e.g., the handle 56 has been moved away from theshaft 22) to reduce the pressure inside of the fluid chamber 34 andaspirate the liquid L from the container 90 into the fluid chamber 34.The seal 61 contributes to maintaining the low suctioned pressure withinthe fluid chamber 34 that allows the instrument 20 to draw the liquid Lfrom the container 90 into the chamber 34.

In one embodiment, the plunger 24 is retracted proximally relative tothe shaft 22 until the distal-most stop detent 72 is engaged with thedetent 52 to maximize the volume of the fluid chamber 34. The checkvalve 50 allows the liquid L in the container 90 to flow into theorifice 36 and into the fluid chamber 34, but prevents the liquid Lwithin the fluid chamber 34 from exiting the orifice 36. In oneembodiment, the relatively low pressure within the fluid chamber 34 asthe liquid L is drawn from the container 90 will draw the expandablemember 26 inward toward the shaft 22, which provides an even morecompact profile for the instrument 20 that contributes to the ease ofinsertion of the shaft 22 into one of the corpora cavernosum areas ofthe patient.

FIG. 5B shows a patient prepped and ready to have the corpora cavernosaC1 and C2 of the penis P measured and subsequently dilated by theinstrument 20 prior to implantation of a penile prosthetic. While thepenile prosthetic is not shown, it would typically include a pair ofinflatable cylinders, a reservoir, and a pump employed to transfer fluidto/from the reservoir.

The fluid chamber 34 (FIG. 5A) has been primed with the liquid L. Theexpandable member 26 of the instrument 20 is in a deflated state (or anon-inflated state) such that the shaft 22 is rigid and has a uniformlysmooth outside diameter suited for measuring a length of one of thecorpora cavernosa C1 or C2. The instrument 20 is employed by insertingthe rigid shaft 22 into the corpora of the penis to first measure thecorpora C1 and C2 with the expandable member 26 not inflated. After thelengths of the corpora C1 and C2 are records the expandable member 26 isdilated to core tissue from the corpora C1 and C2. For example, whilethe instrument 20 is inserted into one of the corpora cavernosum, theexpandable member 26 is expanded to subsequently dilate the corpora forinsertion of the cylinders.

The groin area 100 of the patient is shaved, cleaned and suitablyprepped with a surgical solution prior to draping with a sterile drapeas directed by the healthcare provider's procedures. A retractiondevice, such as a retractor 102 sold under the trademark Lone Star andavailable from Lone Star Medical Products of Stafford, Tex., is placedaround the penis P if so desired by the surgeon to establish asurgically clean field. A catheter 103 is inserted into the urethra Ufrom the distal end 104 of the penis P.

Thereafter, the surgeon forms an incision to access the corporacavernosa C1 and C2 of the penis. One suitable incision includes thetransverse scrotal approach, where the surgeon forms a 2-3 cm transverseincision through the subcutaneous tissue of the median raphe of theupper scrotum Sc and dissects down through the Darto's fascia Df andBuck's fascia Bf to expose the tunicae albuginea TA of the penis P.Thereafter, each corpora cavernosum C1 and C2 is exposed in acorporotomy where a small (approximately 1.5 cm) incision is formed toallow the surgeon to access and subsequently dilate the corporacavernosa C1 and C2.

The penis P is reclined against the torso such that the urethra U,surrounded by corpus spongiosum tissue, is oriented upward. Theinstrument 20 provides a substantially uniform outside diameter that isconfigured to slide into the corpora and allow the shaft 22 to measurethe length of each of the corpora cavernosum (C1 or C2). In the corporameasurement configuration illustrated in FIG. 5B, the entire length ofthe shaft 22 is uniformly unobstructed and suited for easy insertioninto each corpora cavernosum.

The surgeon typically will insert a blunt-ended scissors or otherelongated tool to separate a portion of the spongiosum material to opena pathway for the instrument 20. The surgeon inserts the shaft 22 intothe corpora cavernosa C1 and C2 to measure the proximal and distallength of each corpora cavernosum C1 and C2. For example, the shaft 22is inserted into one of the corpora cavernosa C1 or C2 forward in thedistal penis toward the glans penis, the distal measurement is recordedby reading the indicia 39, and the shaft 22 is inserted into the samecorpora cavernosa C1 or C2 rearward in the proximal penis toward thecrus, of the penis to record the proximal length of the corpora byreading the indicia 39. The distal and proximal measurements wouldtypically be made in reference to a “stay stitch” temporarily placed inthe incision. The sum of the distal and the proximal measurementsrepresent the length of the corpora into which the implant is placed.This procedure is repeated for the other of the corpora cavernosa C1 orC2 to measure the length of the companion corpora.

Thereafter, each corpora cavernosum C1 and C2 is dilated distally andproximally with the instrument 20. One exemplary method of preparing anopening formed in the penis P for reception of a penile prostheticincludes aspirating a fluid through the orifice 38 formed in the distalend 32 of the shaft 22; measuring a length of the opening in the corporaof the penis with the shaft 22; expanding, with the fluid, the balloon26 that is attached to the shaft; and dilating a diameter of the openingformed in the penis with the expanded balloon. In one embodiment, theinstrument 20 is employed to first measure the length of each corporacavernosum C1 and C2, and while the instrument is still inserted intoone of the corpora cavernosum C1 and C2, the expandable member 26 isdilated to a first expanded diameter in a controlled manner through theuse of the detent 52 and the stop detents 72, the corpora cavernosum isdilated to the first diameter, and then the expandable member 26 isdilated to a second larger expanded diameter by indexing to the nextstop detent 72, where the corpora cavernosum is dilated to the seconddiameter.

FIG. 5C illustrates the instrument 20 with the expandable member 26pressurized by the liquid L and dilated to a diameter that is largerthan the diameter D1 of the shaft 22 (see FIG. 4B). The check valve 50prevents the liquid L from exiting the orifice 36 at the distal end 32of the shaft 22 as the plunger 24 pressurizes the liquid L. The expandeddistal end portion 42 of the instrument 20 is inserted first proximallyand then distally into one of the corpora C1 or C2 to dilate the corporato the expanded diameter provided by expandable member 26. In a likemanner, the surgeon would insert the distal end 32 of the instrument 20first proximally and then distally into the other of the corpora C1 orC2 to dilate the other corpora to the diameter of the expanded member 26of instrument 20.

The instrument 20 is configured to provide the surgeon with the optionof first dilating the corpora to the diameter D1 of the shaft 22 (FIG.4B), incrementally advancing the plunger 24 into the shaft 22 to expandthe expandable member 26 to dilate the corpora to a diameter D2, andagain incrementally advancing the plunger 24 into the shaft 22 to expandthe expandable member 26 to dilate the corpora to a diameter D3.

In one embodiment, the plunger 24 is advanced into the shaft 22 until afirst one of the stop detents 72 engages with the detent 52 and theexpandable member 26 inflates from the diameter D1 of the shaft 22 to asecond diameter that is approximately 125% of the diameter D1, afterwhich the surgeon dilates the corpora to approximately the seconddiameter; the plunger 24 is incrementally advanced into the shaft 22until a next one of the stop detents 72 engages with the detent 52 andthe expandable member 26 further inflates to a third diameter that isapproximately 150% of the diameter D1, after which the surgeon dilatesthe corpora to approximately the third diameter; and the plunger 24 isincrementally advanced into the shaft 22 until a next one of the stopdetents 72 engages with the detent 52 and the expandable member 26further inflates to a fourth diameter that is approximately 150% of thediameter D1, after which the surgeon dilates the corpora toapproximately the fourth diameter. In one embodiment, the instrument 20is beneficially configured such that the first end or is about 8 mm, thesecond diameter is about 10 mm, the third diameter is about 12 mm, andthe fourth diameter is about 14 mm, although any suitable range of fromD1 of about 2 mm to D4 of about 20 mm is acceptable.

In one embodiment, the plunger 24 is retracted proximally relative tothe shaft 22 to deflate the balloon/expandable member 26 to the diameterof D1 as the surgeon transitions between dilating the corpora betweenthe second diameter, the third diameter, and the fourth diameter.

After dilation of the corpora cavernosum C1 and C2, the surgeon selectsa proper length of implant and proceeds with placement of cylinders ofthe implant within the fully dilated corpora.

Embodiments provide an instrument that is configured to prepare a penisfor implantation of a penile prosthetic, where the instrument includes ashaft suited for measuring a length of the corpora cavernosum and aplunger that is movable relative to the shaft to inflate an expandablemember away from the shaft, thus widening the shaft in a manner thatwill dilate the corpora cavernosum. Thus, a single instrument isprovided that has improved cost effectiveness and procedural efficiencyover the prior tools, and is suited to measure and dilate the corporacavernosum of the penis.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat a variety of alternate and/or equivalent implementations may besubstituted for the specific embodiments shown and described withoutdeparting from the scope of the present invention. This application isintended to cover any adaptations or variations of medical devices asdiscussed herein. Therefore, it is intended that this invention belimited only by the claims and the equivalents thereof.

1. An instrument configured to prepare a penis for implantation of apenile prosthetic, the instrument comprising: a rigid shaft extendingbetween a proximal end and a distal end that is insertable into thepenis; and an expandable member coupled to a distal end portion of theshaft, the expandable member movable between a first position having afirst diameter that is substantially equal to a diameter of the rigidshaft and a second position having a second diameter that is larger thanthe diameter of the rigid shaft and configured to dilate tissue of thepenis.
 2. The instrument of claim 1, further comprising: a fluid chamberformed in the shaft; an orifice formed in the distal end of the shaftthrough which fluid is drawn from outside the shaft into the fluidchamber; a fluid pathway formed in the shaft communicating between thefluid chamber and the expandable member; and a plunger movably insertedinto the fluid chamber.
 3. The instrument of claim 2, furthercomprising: a check valve in the distal end portion of the shaftproximal the orifice, the check valve configured to prevent the fluid inthe fluid chamber from exiting the distal end of the shaft.
 4. Theinstrument of claim 1, wherein the expandable member is inflatable andthe second diameter is approximately 125% to 200% of the first diameter.5. An instrument configured to prepare a penis for implantation of apenile prosthetic, the instrument comprising: a shaft extending betweena distal end and a proximal end, a fluid chamber formed inside theshaft, the distal end of the shaft including an orifice through whichfluid is drawn from outside the shaft into the fluid chamber; a plungermovably inserted into the fluid chamber; an expandable member sealed toa distal end portion of the shaft; and a fluid pathway formed in theshaft communicating between the fluid chamber and the expandable member;wherein the plunger is movable to inflate the expandable member awayfrom the shaft.
 6. The instrument of claim 5, wherein the fluid chamberis formed as an axial bore extending between the distal and proximalends of the shaft.
 7. The instrument of claim 6, wherein the plunger ismovably inserted into the fluid chamber via the proximal end of theshaft and comprises a rod having a seal that contacts the axial bore. 8.The instrument of claim 5, wherein the distal end portion of the shaftincludes a check valve located proximal the orifice, the check valveconfigured to prevent the fluid in the fluid chamber from exiting thedistal end of the shaft.
 9. The instrument of claim 5, wherein anexterior surface of the distal end portion of the shaft includes arecessed shoulder, the expandable member sealed to the recessedshoulder.
 10. The instrument of claim 5, wherein the expandable memberis sealed around a periphery of the distal end portion of the shaft. 11.The instrument of claim 10, wherein the distal end portion of the shaftis recessed relative to a proximal end portion of the shaft.
 12. Theinstrument of claim 11, wherein the expandable member is disposed in therecessed distal end portion of the shaft.
 13. The instrument of claim12, wherein the expandable member configures the shaft to provide asubstantially uniform diameter between the proximal and distal endportions when the expandable member in its deflated state.
 14. Theinstrument of claim 5, wherein the shaft has a shaft diameter and theexpandable member is inflatable from a first diameter approximatelyequal to the shaft diameter to a second diameter that is approximately125% of the shaft diameter.
 15. The instrument of claim 14, wherein theexpandable member is inflatable to a second diameter that isapproximately 150% of the shaft diameter.
 16. The instrument of claim14, wherein the expandable member is inflatable to a second diameterthat is approximately 200% of the shaft diameter.
 17. The instrument ofclaim 5, wherein the plunger is movable longitudinally relative to theshaft and the expandable member is movable laterally relative to theshaft.
 18. An instrument configured to prepare a penis for implantationof a penile prosthetic, the instrument comprising: a shaft extendinglongitudinally between a distal end and a proximal end, the distal endof the shaft including an orifice configured to draw fluid from outsidethe shaft into the shaft; a bulb sealed to an exterior side surface ofthe shaft; and means for pressurizing the fluid and expanding the bulbaway from the exterior side surface of the shaft.
 19. The instrument ofclaim 18, further comprising: means for preventing the fluid drawn fromoutside the shaft into the shaft from exiting the shaft.
 20. Theinstrument of claim 18, further comprising: means for controllingexpansion of the bulb from a first diameter to a second diameter that islarger than the first diameter.
 21. An instrument configured to form anopening in a penis for implantation of a penile prosthetic, theinstrument comprising: a shaft extending between a distal end and aproximal end; a plunger coupled to and movable relative to the shaft; anexpandable dilation head coupled to a distal end portion of the shaft;and means for expanding the expandable dilation head laterally away fromthe shaft.
 22. The instrument of claim 21, further comprising: means fordrawing fluid through an orifice formed in the distal end of the shaftand into a chamber formed inside of the shaft including means forpreventing the fluid from exiting the chamber through the orifice. 23.The instrument of claim 21, further comprising: means for expanding theexpandable dilation head laterally away from the shaft to a seconddistance and maintain the dilation head at the second distance away fromthe shaft.